Showing papers on "Ferroelectricity published in 2023"
18 citations
TL;DR: Despite the fact that relaxor ferroelectrics have been extensively researched because of their various advantages, there are still barriers to corporately increasing energy storage density (Wrec) and efficiency (η) as discussed by the authors .
Abstract: Despite the fact that relaxor ferroelectrics (RFEs) have been extensively researched because of their various advantages, there are still barriers to corporately increasing energy storage density (Wrec) and efficiency (η)....
17 citations
TL;DR: In this article , a design of crossover relaxor ferroelectric state with high maximum polarization and small remanent polarization at moderate electric fields, a large Wrec of 3.95 J/cm3 and an excellent η of 85.9 % was obtained in 0.85(0.67BiFeO3-0.33BaTiO3)-0.15SNA ceramic.
15 citations
TL;DR: In this paper , the authors show that bilayer Td-MoTe2 simultaneously exhibits ferroelectric switching and superconductivity, and show that the superconducting transition temperature is concomitant with compensated electron and hole carrier densities and vanishes when one of the Fermi pockets disappears with doping.
Abstract: Achieving electrostatic control of quantum phases is at the frontier of condensed matter research. Recent investigations have revealed superconductivity tunable by electrostatic doping in twisted graphene heterostructures and in two-dimensional semimetals such as WTe2 (refs. 1–5). Some of these systems have a polar crystal structure that gives rise to ferroelectricity, in which the interlayer polarization exhibits bistability driven by external electric fields6–8. Here we show that bilayer Td-MoTe2 simultaneously exhibits ferroelectric switching and superconductivity. Notably, a field-driven, first-order superconductor-to-normal transition is observed at its ferroelectric transition. Bilayer Td-MoTe2 also has a maximum in its superconducting transition temperature (Tc) as a function of carrier density and temperature, allowing independent control of the superconducting state as a function of both doping and polarization. We find that the maximum Tc is concomitant with compensated electron and hole carrier densities and vanishes when one of the Fermi pockets disappears with doping. We argue that this unusual polarization-sensitive two-dimensional superconductor is driven by an interband pairing interaction associated with nearly nested electron and hole Fermi pockets. The authors show a hysteretic behaviour of superconductivity as a function of electric field in bilayer Td-MoTe2, representing observations of coupled ferroelectricity and superconductivity.
15 citations
TL;DR: In this article , Ca doped BFO nanoparticles Bi0.9Ca0.1FeO3 (BCFO) were prepared by sol-gel method and two morphologies were obtained by controlling the time of loading CdS under a low temperature liquid phase process.
Abstract: BiFeO3 (BFO), as a kind of narrow band-gap semiconductor material, has gradually emerged advantages in the application of photocatalysis. In this paper, Ca doped BFO nanoparticles Bi0.9Ca0.1FeO3 (BCFO) were prepared by sol-gel method. And BCFO and CdS nanocomposites with two morphologies were obtained by controlling the time of loading CdS under a low temperature liquid phase process. It is found that the band gap becomes narrower after doping Ca into BFO, which is conducive to the absorption of visible light. Among all the samples, the composite of CdS nanowires and BCFO nanoparticles obtained by reaction time of 10 min has the best photocatalytic performance. The degradation rate of Methyl Orange solution was 94% after 90 min under visible light irradiation, which was much higher than that of pure BCFO and CdS. Furthermore, significant enhancement in the degradation rate (100% degradation in 60 min) can be achieved in poled samples after electric polarization process. The highest degradation rate is due to the promoted separation of photogenerated carriers induced by the internal polarization field and the formation of S-scheme heterostructure between BCFO and CdS. Such BCFO-CdS nanocomposites may bring new insights into designing highly efficient photocatalyst.
13 citations
TL;DR: In this paper , the microscopic mechanism of the occurrence of ferroelectric properties in M-type barium hexaferrites is investigated by experimental and first-principle computation methods.
11 citations
TL;DR: The ternary system of BaTiO 3 (BT) -based lead-free ceramics ((1- x )BaTiO3 - x (0.94Sr 0.7 Bi 0.06BiMg 0.5 Ti 0.2 TiO 3 -0.5 O 3 ) is investigated on their structural, dielectric and ferroelectric properties as discussed by the authors .
9 citations
TL;DR: In this paper , a defect-engineered morphotropic phase boundary was proposed to achieve a giant strain of 1.12% in lead-free Bi 0.5Na0.5TiO3 (BNT) based ceramics.
Abstract: Piezoelectric ceramics have been extensively used in actuators, where the magnitude of electrostrain is key indicator for large-stroke actuation applications. Here, we propose an innovative strategy based on defect chemistry to form a defect-engineered morphotropic phase boundary and achieve a giant strain of 1.12% in lead-free Bi0.5Na0.5TiO3 (BNT)–based ceramics. The incorporation of the hypothetical perovskite BaAlO2.5 with nominal oxygen defect into BNT will form strongly polarized directional defect dipoles, leading to a strong pinning effect after aging. The large asymmetrical strain is mainly attributed to two factors: The defect dipoles along crystallographic [001] direction destroy the long-range ordering of the ferroelectric and activate a reversible phase transition while promoting polarization rotation when the dipoles are aligned along the applied electric field. Our results not only demonstrate the potential application of BNT-based materials in low-frequency, large-stroke actuators but also provide a general methodology to achieve large strain.
9 citations
TL;DR: In this article , the authors report on the thickness scaling behavior of ferroelectric Sc0.3Al0.7N (ScAlN) films grown on Mo substrates by molecular beam epitaxy and show that the increase in coercive field and diminishment in switchable polarization can be linked to the surface oxidation and strain state in ultrathin ScAlN films.
Abstract: We report on the thickness scaling behavior of ferroelectric Sc0.3Al0.7N (ScAlN) films grown on Mo substrates by molecular beam epitaxy. Switchable ferroelectricity is confirmed in ScAlN films with thicknesses ranging from 100 to 5 nm. An increase in coercive field and a significant diminution of remnant polarization are found when the ferroelectric layer is scaled down to below 20 nm. Notably, a switching voltage of 2–3.8 V and saturated remnant polarization of ∼23 μC/cm2 are measured in 5 nm thick ScAlN. X-ray diffractions and transmission electron microscopy studies indicate that the increase in coercive field and diminishment in switchable polarization can be closely linked to the surface oxidation and strain state in ultrathin ScAlN films. This work sheds light on the fundamental thickness scaling fingerprints of ScAlN thin films and represents an important step for next-generation compact and power-efficient devices and applications based on nitride ferroelectrics.
9 citations
7 citations
TL;DR: In this article , a flexible photodetector integrated by ferroelectric BaTiO3 (BTO) nanofibers was developed via electrospinning technology with double sprinklers and in situ heat treatment.
Abstract: The flexible titanium dioxide (TiO2) nanofibers (NFs) film are promising candidates for high‐performance wearable optoelectronic devices. However, the TiO2 ultraviolet photodetectors (UV PDs) generally suffer from low photosensitivity, which limits the practical applications. Herein, a TiO2 (TO) NFs film flexible photodetector integrated by ferroelectric BaTiO3 (BTO) NFs is developed via electrospinning technology with double sprinklers and in situ heat treatment. Compared with TO NFs PD with poor on/off ratio ≈44, the BTO@TO NFs PD‐2 exhibits an excellent on/off ratio of ≈1.5 × 104 due to the dramatically restrained dark current. The ultralow dark current (pA level) is attributed to the depletion of photogenerated carriers by the space high‐resistance state induced by the downward self‐polarization field in ferroelectric BaTiO3 NFs. The ferroelectric domain with larger downward orientation in polarized BTO@TO NFs exhibits stronger self‐polarization field to modify the directional transport of photogenerated carriers and enhances the band bending level, which improves the photocurrent of device. The special structure woven by ferroelectric nanofiber with self‐polarization will provide a promising approach for improving the performance of flexible photodetectors.
TL;DR: In this paper , the authors reported room-temperature ferroelectricity, both out-of-plane and in-plane, in vdW-layered γ-InSe semiconductor triggered by yttrium-doping (InSe:Y).
Abstract: Two-dimensional (2D) van-der-Waals (vdW) layered ferroelectric semiconductors are highly desired for in-memory computing and ferroelectric photovoltaics or detectors. Beneficial from the weak interlayer vdW-force, controlling the structure by interlayer twist/translation or doping is an effective strategy to manipulate the fundamental properties of 2D-vdW semiconductors, which has contributed to the newly-emerging sliding ferroelectricity. Here, we report unconventional room-temperature ferroelectricity, both out-of-plane and in-plane, in vdW-layered γ-InSe semiconductor triggered by yttrium-doping (InSe:Y). We determine an effective piezoelectric constant of ∼7.5 pm/V for InSe:Y flakes with thickness of ∼50 nm, about one order of magnitude larger than earlier reports. We directly visualize the enhanced sliding switchable polarization originating from the fantastic microstructure modifications including the stacking-faults elimination and a subtle rhombohedral distortion due to the intralayer compression and continuous interlayer pre-sliding. Our investigations provide new freedom degrees of structure manipulation for intrinsic properties in 2D-vdW-layered semiconductors to expand ferroelectric candidates for next-generation nanoelectronics.
TL;DR: In this paper , a linear dielectric CaTiO3 (CT) additive was introduced into Bi0.5Na 0.6O3-NBNM-0.1CT ceramic to enhance its Eb.
01 Jan 2023
TL;DR: In this paper , a dual cavity dielectric modulated ferroelectric charge plasma tunnel FET (FE-CP-TFET) with enhanced sensitivity was proposed for the detection of biomolecules.
Abstract: This work reports a biosensor based on the dual cavity dielectric modulated ferroelectric charge plasma Tunnel FET (FE-CP-TFET) with enhanced sensitivity. By incorporating underlap and dielectric modulation phenomena, ultra sensitive, and label-free detection of biomolecules is achieved. The cavity is carved underneath the source-gate dielectric for the immobilization of the biomolecules. The ferroelectric (FE) material is used as a gate stack to realize a negative capacitance effect to amplify the low gate voltage. To avoid the issues with metallurgical doping such as random dopant fluctuations (RDFs), ambipolar conduction, and increased thermal budget, the charge plasma concept is deployed. Based on our exhaustive ATLAS 2D TCAD study, the electric field, hole concentration, and energy band diagram of the proposed device are critically analyzed to provide a better insight into the biosensor working mechanism. Here, two different figures-of merits (FOMs) for the proposed biosensor are investigated such as sensitivity and linearity. Sensitivity has been measured in terms of drain current, [Formula: see text] to [Formula: see text] ratio, electric field, and transconductance sensitivity. Linearity analysis of the proposed structure includes [Formula: see text] ratio. The reported biosensor is capable of detecting several biomolecules such as (neutral and charged as well) Streptavidin (2.1), 3-aminopropyltriethoxysilane (APTES) (K =3.57 ), Keratin (K =8 ), T7 (K =6.3 ) and Gelatin (K =12 ). It was observed that the optimized cavity structure demonstrates high drain current sensitivity ( 2.7×108 ) as well as high [Formula: see text] sensitivity ( 1.45×108 ). Further, the linearity analysis shows that the Pearson's coefficient of both structures have been achieved as ( r2 ≥ 0.8 ). It is conferred from the results that our biosensor can be a better alternative for the detection of the various neutral and charged biomolecules.
TL;DR: In this article , the effect of chemical heterogeneity on the dielectric and impedance behaviors of lead-free relaxors was investigated, and it was found that more valence electron defects are generated to cause charge leakage by introducing excess Nb 2 O 5 .
Abstract: Different levels of Nb 2 O 5 substitution in 0.66(Bi 0.5 Na 0.5 )TiO 3 −0.06BaTiO 3 −0.28(Bi 0.2 Sr 0.7 )TiO 3 (BS- x Nb) lead-free relaxors were prepared to investigate the effect of chemical heterogeneity on the dielectric and impedance behaviors. X-ray diffraction reveals that the secondary phase gradually increases in number and intensity as the dopant increases. The substitution of less Nb 5+ for Ti 4+ leads to reduced electronic conductivity and dielectric loss, which is attributed to the inhibition of oxygen vacancies and associated electron. It is found that more valence electron defects are generated to cause charge leakage by introducing excess Nb 2 O 5 . Moreover, the addition of Nb 2 O 5 doping enhances the disorder and facilitates the transition of the nonergodic to ergodic relaxor phase. The ferroelectric ergodic long-range order is further disrupted and promotes the formation of local defect fields and high-temperature polar nanoregions. These effects enhance the relaxation behavior with decreased remnant polarization and form a broadly flat dielectric platform. Meanwhile, BS-2Nb exhibits attractively high recoverable energy storage density and efficiency at a relatively low electric field with stability against frequency and temperature. Combined with the complex impedance characteristics, the leakage contribution of the chemical inhomogeneity introduced by excess Nb 2 O 5 is presented, demonstrating the significance of regulating the dielectric performance of bismuth sodium titanate-based relaxors.
TL;DR: In this paper , the authors investigated the microscopic origin of this effect and showed that converting the bulky chlorofluoroethylene (CFE) into small-size FA defects dramatically weakens the relaxor behavior.
Abstract: Polymers that generate large shape changes under electric stimulation are of great interest for many applications. Recently, it was shown that converting a small amount of chlorofluoroethylene (CFE) in relaxor ferroelectric poly(vinylidene fluoride–trifluoroethylene–CFE) (PVDF-TrFE-CFE) terpolymer into fluorinated alkyne (FA) creates P(VDF-TrFE-CFE-FA) tetrapolymers with giant electromechanical (EM) response at ultralow electric fields (<50 MV/m). We investigate the microscopic origin of this effect and show that converting the bulky CFE into small-size FA defects dramatically weakens the relaxor behavior. Importantly, P(VDF-TrFE-CFE-FA) tetrapolymers with near 2 mol % FA exhibit a diffused critical endpoint transition region at which the energy barriers for switching from nonpolar to polar molecular conformations become small. Consequently, a small change of the electric field induces a large electroactuation, which can enable novel applications. This work opens up a totally new approach to designing ferroelectric polymers that generate large responses at ultralow electric fields.
TL;DR: In this paper , the effect of the annealing temperature of PZT on the structural characteristics of the prepared composite films was investigated using X-ray diffraction and Fourier transform infrared (FTIR) methods.
TL;DR: In this paper , a donor doped BaTiO3 (BT)-based RFE ceramics was introduced to achieve high energy storage density (Wrec), high efficiency (η), wide work temperature range and stable charge discharge ability.
TL;DR: In this article , the orientation and alignment of polar cations, dominated factors in molecular ferroelectrics, can be controlled by easily processed anionic modification, and the experimental and theoretical investigation reveals that ferroelectricity is induced by strengthened intermolecular interaction.
Abstract: Construction of ferroelectric and optimization of macroscopic polarization has attracted tremendous attention for next generation light weight and flexible devices, which brings fundamental vitality for molecular ferroelectrics. However, effective molecular tailoring toward cations makes ferroelectric synthesis and modification relatively elaborate. Here, the study proposes a facile method to realize triggering and optimization of ferroelectricity. The experimental and theoretical investigation reveals that orientation and alignment of polar cations, dominated factors in molecular ferroelectrics, can be controlled by easily processed anionic modification. In one respect, ferroelectricity is induced by strengthened intermolecular interaction. Moreover, ≈50% of microscopic polarization enhancement (from 8.07 to 11.68 µC cm-2 ) and doubling of equivalent polarization direction (from 4 to 8) are realized in resultant ferroelectric FEtQ2ZnBrI3 (FEQZBI, FEtQ = N-fluoroethyl-quinuclidine). The work offers a totally novel platform for control of ferroelectricity in organic-inorganic hybrid ferroelectrics and a deep insight of structure-property correlations.
TL;DR: In this paper , the mechanism of interfacial polarization in barium titanate/poly(vinylidene fluoride-ran-trifluoroethylene) (BTO/P(VDF-TrFE)) nanocomposite is revealed at multiple scales by combining Kelvin probe force microscope (KPFM) with theoretical stimulation.
Abstract: The interfacial effect is widely used to optimize the properties of ferroelectric nanocomposites, however, there is still a lack of direct evidence to understand its underlying mechanisms limited by the nano size and complex structures. Here, taking piezoelectricity, for example, the mechanism of interfacial polarization in barium titanate/poly(vinylidene fluoride-ran-trifluoroethylene) (BTO/P(VDF-TrFE)) nanocomposite is revealed at multiple scales by combining Kelvin probe force microscope (KPFM) with theoretical stimulation. The results prove that the mismatch of permittivity between matrix and filler leads to the accumulation of charges, which in turn induces local polarization in the interfacial region, and thus can promote piezoelectricity independently. Furthermore, the strategy of interfacial polarization to enhance piezoelectricity is extended and validated in other two similar nanocomposites. This work uncovers the mechanism of interfacial polarization and paves newfangled insights to boost performances in ferroelectric nanocomposites.
TL;DR: In this article , a reduced graphene oxide (rGO)-MoS2 heterostructure is designed to tackle the challenges of finite active sites, catalyst poisoning, and poor conductivity for developing good piezocatalysts.
Abstract: The catalytic activity has been investigated in 2D materials, and the unique structural and electronic properties contribute to their success in conventional heterogeneous catalysis. Heterojunction‐based piezocatalysis has attracted increasing attention due to the band‐structure engineering and the enhanced charge carrier separation by prominent piezoelectric effect. However, the piezocatalytic behavior of van der Waals (vdW) heterostructures is still unknown, and the finite active sites, catalyst poisoning, and poor conductivity are challenges for developing good piezocatalysts. Herein, a reduced graphene oxide (rGO)‐MoS2 heterostructure is rationally designed to tackle these challenges. The heterostructure shows a record‐high piezocatalytic degradation rate of 1.40 × 102 L mol−1 s−1, which is 7.86 times higher than MoS2 nanosheets. Piezoresponse force microscope measurements and density functional theory calculation reveal that the coupling between semiconductive and piezoelectric properties in the vdW heterojunction is vital to break the metallic state screening effect at the MoS2 edge for keeping the piezoelectric potential. The dynamic charges generated by MoS2 and the fast charge transfer in rGO activate and maintain catalytically active sites for pollutant degradation with an ultra‐fast rate and good stability. The working mechanism opens new avenues for developing efficient catalysts significant to wastewater treatments and other applications.
TL;DR: In this paper , the authors demonstrate that MnSe multilayers constructed by the recently-synthesized MnSe monolayer have large sliding-driven reversible out-of-plane electric polarization (~10.6 pC m −1 ) and moderate interlayer sliding barriers superior to the existing 2D SFE materials.
Abstract: Abstract Sliding ferroelectricity (SFE) found in two-dimensional (2D) van der Waals (vdW) materials, such as BN and transition-metal dichalcogenides bilayers, opens an avenue for 2D ferroelectric materials. Multiferroic coupling in 2D SFE materials brings us an alternative concept for spintronic memory devices. In this study, using first-principles calculations, we demonstrate that MnSe multilayers constructed by the recently-synthesized MnSe monolayer have large sliding-driven reversible out-of-plane electric polarization (~10.6 pC m −1 ) and moderate interlayer sliding barriers superior to the existing 2D SFE materials. Interestingly, the intrinsic electric polarization is accompanied by nonzero net magnetic moments which are also switchable via lateral interlayer sliding. Additionally, both SFE and magnetoelectric coupling can be effectively regulated by external strain and/or hole doping. Our findings suggest the potential of MnSe multilayers in 2D multiferroic and spintronic applications.
TL;DR: In this paper , a simple integrated process and high-performance photodetector based on an α-In2Se3/Si vertical hybrid-dimensional heterojunction was constructed, which achieved a self-powered, highly sensitive photoresponse with an on/off ratio of 4.5 × 105 and detectivity of 1.6 × 1013 Jones.
Abstract: Photodetectors have been applied to pivotal optoelectronic components of modern optical communication, sensing, and imaging systems. As a room-temperature ferroelectric van der Waals semiconductor, 2D α-In2Se3 is a promising candidate for a next-generation optoelectronic material because of its thickness-dependent direct bandgap and excellent optoelectronic performance. Previous studies of photodetectors based on α-In2Se3 have been rarely focused on the modulated relationship between the α-In2Se3 intrinsic ferroelectricity and photoresponsivity. Herein, a simple integrated process and high-performance photodetector based on an α-In2Se3/Si vertical hybrid-dimensional heterojunction was constructed. Our photodetector in the ferroelectric polarization up state accomplishes a self-powered, highly sensitive photoresponse with an on/off ratio of 4.5 × 105 and detectivity of 1.6 × 1013 Jones, and it also shows a fast response time with 43 μs. The depolarization field generated by the remanent polarization of ferroelectrics in α-In2Se3 provides a strategy for enhancement and modulation of photodetection. The negative correlation was discovered because the enhancement photoresponsivity factor of ferroelectric modulation competes with the photovoltaic behavior within the α-In2Se3/Si heterojunction. Our research highlights the great potential of the high-efficiency heterojunction photodetector for future object recognition and photoelectric imaging.
TL;DR: In this article , a rapid and effective therapeutic strategy to treat osteomyelitis through ferroelectric polarization interfacial engineering of BiFeO3/MXene (Ti3C2) triggered by ultrasound (US) is reported.
Abstract: Bacteria‐infected osteomyelitis is life‐threatening without effective therapeutic methods clinically. Here, a rapid and effective therapeutic strategy to treat osteomyelitis through ferroelectric polarization interfacial engineering of BiFeO3/MXene (Ti3C2) triggered by ultrasound (US) is reported. Under US, the ferroelectric polarization induces the formation of the piezoelectric field. US cavitation effect induced sonoluminescence stimulates BiFeO3/Ti3C2 to produce photogenerated carriers. With synergistic action of the polarization electric field and Schottky junction, BiFeO3/Ti3C2 accelerates the separation of electrons and holes and simultaneously inhibits the backflow of electrons, thus improving the utilization of polarized charges and photogenerated charges and consequently enhancing the yield of reactive oxygen species under US. As a result, 99.87 ± 0.05% of Staphylococcus aureus are efficiently killed in 20 min with the assistance of ultrasonic heating. The theory of ferroelectric ultrasonic interfacial engineering is proposed, which brings new insight for developing ferroelectric ultrasonic responsive materials used for the diagnosis and therapy of deep tissue infection and other acoustoelectric devices.
TL;DR: In this article , the internal electric field and ferroelectric polarization via the modulation of surface electronic structures to achieve high carrier separation efficiency is proposed for solar-to-chemical energy conversion.
Abstract: Coupling the internal electric field and ferroelectric polarization via the modulation of surface electronic structures to achieve high carrier separation efficiency is attractive but challenging in solar-to-chemical energy conversion.
TL;DR: In this article , a single subnanosecond pulse can fully switch HfO2-based FeFETs and the polarization switching kinetics across 11 orders of magnitude in time (300 ps to 8 s).
Abstract: The discovery of ferroelectric doped HfO2 enabled the emergence of scalable and CMOS-compatible ferroelectric field-effect transistor (FeFET) technology which has the potential to meet the growing need for fast, low-power, low-cost, and high-density nonvolatile memory, and neuromorphic devices. Although HfO2 FeFETs have been widely studied in the past few years, their fundamental switching speed is yet to be explored. Importantly, the shortest polarization time demonstrated to date in HfO2-based FeFET was ∼10 ns. Here, we report that a single subnanosecond pulse can fully switch HfO2-based FeFET. We also study the polarization switching kinetics across 11 orders of magnitude in time (300 ps to 8 s) and find a remarkably steep time-voltage relation, which is captured by the classical nucleation theory across this wide range of pulse widths. These results demonstrate the high-speed capabilities of FeFETs and help better understand their fundamental polarization switching speed limits and switching kinetics.
TL;DR: In this paper , a room-temperature 2D layered ferroelectric semiconductor, bismuth oxychalcogenides (Bi2O2Se), is investigated with a thickness down to 7.3 nm (≈12 layers) and piezoelectric coefficient (d33) of 4.4 ± 0.1 pm V−1.
Abstract: Atomically 2D layered ferroelectric semiconductors, in which the polarization switching process occurs within the channel material itself, offer a new material platform that can drive electronic components toward structural simplification and high‐density integration. Here, a room‐temperature 2D layered ferroelectric semiconductor, bismuth oxychalcogenides (Bi2O2Se), is investigated with a thickness down to 7.3 nm (≈12 layers) and piezoelectric coefficient (d33) of 4.4 ± 0.1 pm V−1. The random orientations and electrically dependent polarization of the dipoles in Bi2O2Se are separately uncovered owing to the structural symmetry‐breaking at room temperature. Specifically, the interplay between ferroelectricity and semiconducting characteristics of Bi2O2Se is explored on device‐level operation, revealing the hysteresis behavior and memory window (MW) formation. Leveraging the ferroelectric polarization originating from Bi2O2Se, the fabricated device exhibits “smart” photoresponse tunability and excellent electronic characteristics, e.g., a high on/off current ratio > 104 and a large MW to the sweeping range of 47% at VGS = ±5 V. These results demonstrate the synergistic combination of ferroelectricity with semiconducting characteristics in Bi2O2Se, laying the foundation for integrating sensing, logic, and memory functions into a single material system that can overcome the bottlenecks in von Neumann architecture.
TL;DR: In this article , a ferroelectric-controlling van der Waals photodetector with vertically stacked two-dimensional (2D) black phosphorus (BP)/indium selenide (In2Se3) was proposed to realize high-sensitivity photoder.
Abstract: Owing to the large built‐in field for efficient charge separation, heterostructures facilitate the simultaneous realization of a low dark current and high photocurrent. The lack of an efficient approach to engineer the depletion region formed across the interfaces of heterojunctions owing to doping differences hinders the realization of high‐performance van der Waals (vdW) photodetectors. This study proposes a ferroelectric‐controlling van der Waals photodetector with vertically stacked two‐dimensional (2D) black phosphorus (BP)/indium selenide (In2Se3) to realize high‐sensitivity photodetection. The depletion region can be reconstructed by tuning the polarization states generated from the ferroelectric In2Se3 layers. Further, the energy bands at the heterojunction interfaces can be aligned and flexibly engineered using ferroelectric field control. Fast response, self‐driven photodetection, and three‐orders‐of‐magnitude detection improvements are achieved in the switchable visible or near‐infrared operation bands. The results of the study are expected to aid in improving the photodetection performance of vdW optoelectronic devices.